Preparation of catalysts



Patented Aug. 25, 1953 UNITED STATES 2,650,204 PREPARATION OF CATALYSTS Peter William Reynolds and Anthony Arthur Leonard Challis, Norton-on-Tees, England, as-

signors to Imperial Che ited, a corporation of G No Drawing.

Claims.

This invention relates to the production of catalysts.

It has already been proposed to prepare metallic catalysts by the partial or complete extraction of an alkali-soluble metal together with a catalytically active metal by treatment with alkali. This process has the disadvantage that the catalyst so prepared is liable to be contaminated with an alkali metal derivative, the presence of Which may adversely effect th chemical reaction in which the catalyst is being used, or it may lead to a deterioration in the activity of the catalyst.

According to the present invention, foraminate catalysts comprising one or more metal selected from copper, cobalt, nickel and iron, are prepared by treating an alloy of one or more of these metals with silicon and/or aluminum at a temperature in excess of 100 C., with a phenol, or a monohydric aliphatic alcohol containing not more than four carbon atoms, to extract a portion of the silicon and/ or aluminum.

By the term foraminate catalyst as used in this specification is meant one comprising particles or pieces, for example granule prepared by ture resulting from the partial or complete remetal or metals from the aforesaid phase or phases in said outer layer. cles or pieces may be prepared in various sizes, but are preferably to I preparing catalysts by the process of the present invention it is preferred to extract the aluminum and/or silicon by the use of a monohydric phenol, preferably containing not more than 8 carbon atoms. Phenol itself is very suitable for use in the extraction. It is also possible to use alcohols containing not more than 4 carbon atoms.

The extraction may be carried out with the in either the liquid or vapour Under normal condition of operation, i. e., working at atmospheric pressure, it is suitable to employ the phenol in the liquid phase and the alcohol in the vapour phase. The temperature at which the extraction is carried out should be in excess of 100 C. and preferably within the range of 180 to 300 C. It is found in the treat- The partimica] Industries Limreat Britain Application April 28, 1950, Serial In Great Britain May 4, 1949 under the preferred conditions, a portion of the silicon can be removed, apparently as an alkyl or aryl silicate. Similarly by the treatment of an alloy containing one or more of the catalytically active metals together with aluminum, a portion of the aluminum can be removed, apparently as an aluminum alkoxide or aryloxide.

It is not necessary for the phenol or alcohol to be completely dried prior to use, but the water content should preferably not exceed that present in commercial samples of the phenol or alcohol.

In preparing these foraminate catalysts, not more than by weight of the initial silicon and/or aluminum content should be extracted.

ing rise to Raney-type catalysts.

Suitable alloys for the operation of the present invention are, for example, copper-aluminum alloys containing from 40 to by weight of copper, copper-silicon alloys containing from 50 to 9 by weight of copper, cobalt-aluminum alloys containing from 15 to 55% by weight of co taining 30 to 65% by weight of nickel, nickelsilicon alloys containing 30 to by weight of nickel, and iron-aluminum alloys containing 30 to 60% by weight of iron. The alloy from which the catalysts are prepared may be employed for example in the form of granules grading between and 1", but more preferably granules grading between A3" and are employed.

In the preparation of foraminate catalysts from ploy alkali as the extracting agent. This, under certain circumstances, gives rise to contamination of the activated catalyst by alkali metal comeffect upon the catalyst activity, and also promote undesired side reactions. In contrast to this, the present invention provides a method for treatment with a phenol or alcohol and this reactivation may frequently be carried out without removing the catalyst from the converter.

The total aluminum must not exceed 70% by weight of the initial content;

It is'a further feature of the invention that when a phenol or alcoholis used as a starting material, or admixed with the starting material, or produced in the process, the catalyst reactiva tion will occur progressively,

Example 1 .100 mls. of a copper-silicon alloy containin 85% by weight of copper and 15% by weight of silicon were placed in a vertical tube heated to 200 C. by an external electric winding. A layer of silica chips was placed on the top of the bed of alloy and liquid methanol was introduced at the top of the tube at a rate of 100 mls. per hour. The methanol was vaporised and passed downwards over the alloy. The extraction was continued until 2 80 mls. of liquid methanol had been introduced into the tube. By this time, 15.9 litres of hydrogen had been evolved, as a result of the reaction between methanol and the silicon. This corresponds to a 19% by weight removal of the initial silicon content.

6 mls. of the catalyst were charged to a converter and used for the hydrogenation of nitrobenzene to aniline. The reaction was carried out at a temperature of 300 C., using a nitro-benzene feed rate of 11 mls. of liquid per hour and a hydrogen rate of 40 litres per hour. Under these conditions 20% of the nitro-benzene was converted to aniline.

Example 2 Example 3 1 mls. of a nickel-silicon alloy containing 50% by weight of nickel and 50% by weight of silicon were activated by treatment for 1 hour with methanol under the conditions described in EX. ample 1 The activated catalyst showed the re-. moval of 8% of the initial silicon content.

Example 4 25 grams of a copper-aluminum alloy containing 55% by weight of copper were refluxed for 16 hours with 250 mls. of phenol. At the end or" this time, the activated catalyst showed the removal of 9% of the initial aluminium content.

We claim:

1. A process for the preparation of a foraminate catalyst comprising at least one catalytic metal selected from the group consisting of copper, cobalt, nickel and iron which comprises treating an alloy selected from the group consisting of copper-aluminum containing from 40 to 80% by weight of copper, copper-silicon containing from 50 to 92% by weight of copper, cobaltaluminum containing from to 55% by weight of cobalt, cobalt-silicon containing from 30 to 75% by weight of cobalt, nickel-aluminum containing from 30 to 65 by weight of nickehnickele and/or silicon removalsilicon containing from 30 to 85% by weight of nickel, and iron-aluminum containing from 30 to by weight of iron at a temperature of from at least 100 to 300 C. with an organic hydroxyl compound selected from the group consisting of monohydric aliphatic alcohols containing at most four carbon atoms and phenols for a time sufficient to extract a substantial portion of and not more than of the extractible elemen 2. A process as set forth in claim 1 wherein the extraction is carried out at a temperature of 180 to 300 C.

. 3. A process for the preparation of a catalyst which comprises treating at a temperature of from at least 100 C. .to 300 C. an alloy of copper and silicon containing from 50 to, 92% by weight of copper in the liquid phase with phenol maintained at its boiling point fora time sufficient to extract a substantial portion of and not more than 70% of the silicon.

4;. A process for the preparation of a foramie nate catalyst comprising at least one catalytic metal selected from the group consisting of copper, cobalt, nickel and iron which comprises treating an alloy selected from the group consist-.-. ing of copper-aluminum containing from 40. to by weight of copper, copper-silicon contain: ing from 50 to 92% by weight of copper, cobaltaluminum containing from 15 to 5.5% by weight of cobalt, cobalt-silicon containing from 3.0. to 75% by weight of cobalt, nickel-aluminum con: taining from 30 to 65% by weight of nickel, nickel-silicon containing from 30 to by weight of nickel and iron-aluminum containing from 30 to 60% phase at a temperature of from at least to 300 C. with a monohydric phenol containing at most eight carbon atoms for a time sufiicient to extract a substantial portion of and not more than 70% of the extractible element.

5,. A process for the preparation of a foraminate catalyst comprising at least one catalytic metal selected from the group consisting of copper, co.-. balt, nickel and iron which comprises. treating an alloy selected from the group consisting of copperaluminurn containing from 40 to 80% by weight of copper, copper-silicon containing from 50 to 92% by weight of copper, cobaltealuminum con-.- taining from 15 to 55% bait-silicon containing from 30 to 75% by weight of cobalt, nickel-aluminum containing from 3.0. to 65% by weight of nickel, nickel silicon COD-1 taining from 30 to 35% by weightv of nickel and iron-aluminum containing from 30 to 60% by weight of iron in the vapor phase at a tempera; ture of from at least 100 to 300 C. with a mono hydric aliphatic alcohol containing at most four carbon atoms for a time suificient to extract a substantial portion of and not more, than 70% of the extractible element.

foraminate PETER WILLIAM REYNOLDS. ANTHONY ARTHUR LEONARD CI-IALLIS.

References Cited in the file of this patent UNITED STATES PATENTS by weight of iron in the liquid by weight of cobalt, cos. 

4. A PROCESS FOR THE PREPARATION OF A FORAMINATE CATALYST COMPRISING AT LEAST ONE CATALYTIC METAL SELECTED FROM THE GROUP CONSISTING OF COPPER, COBALT, NICKEL AND IRON WHICH COMPRISES TREATING AN ALLOY SELECTED FROM THE GROUP CONSISTING OF COPPER-ALUMINUM CONTAINING FROM 40 TO 80% BY WEIGHT OF COPPER, COPPER-SILICON CONTAINING FROM 50 TO 92% BY WEIGHT OF COPPER, COBALTALUMINUM CONTAINING FROM 15 TO 55% BY WEIGHT OF COBALT, COBALT-SILICON CONTAINING FROM 30 TO 75% BY WEIGHT OF COBALT, NICKEL-ALUMINUM CONTAINING FROM 30 TO 65% BY WEIGHT OF NICKEL, NICKEL-SILICON CONTAINING FROM 30 TO 85% BY WEIGHT OF NICKEL AND IRON-ALUMINUM CONTAINING FROM 30 TO 60% BY WEIGHT OF IRON IN THE LIQUID PHASE AT A TEMPERATURE OF FROM AT LEAST 100* TO 300* C. WITH A MONOHYDRIC PHENOL CONTAINING AT MOST EIGHT CARBON ATOMS FOR A TIME SUFFICIENT TO EXTRACT A SUBSTANTIAL PORTION OF AND NOT MORE THAN 70% OF THE EXTRACTIBLE ELEMENT. 